The present invention relates to light sensitive elements or more particularly to photosensitive elements suitable for use as lithographic printing plates or photoresists.
In the production of lithographic printing plates, a hydrophilized metal sheet substrate, usually aluminum is with a photosensitive composition. This photosensitive composition is exposed to ultraviolet radiation through a photomask and developed with a suitable developer composition. The resultant plate can then be employed on a printing press to produce thousands of image reproductions.
Heretofore, the photosensitive component has been applied to the substrate by a mechanical coating means. That is, the coating has been either manually wiped on to the substrate, whirler coated, brushed or sprayed on the surface. The most common application means include gravure coating; dipping an aluminum web through a bath of the photosensitive material and doctoring off the excess; and meniscus coating methods which are well known to the skilled artison.
The present application improves upon these coating methods by electrodepositing the photosensitive component onto the hydrophilized substrate surface. The result is a photographic element having improved adhesion between the photosensitive composition and the hydrophilized substrate surface. When the thusly produced plate is exposed and developed, the image formed is observed to exhibit relatively high resolution and intensity. It displays exceptional light speed and excellent uniform adhesion and abrasion resistance.